In a known door structure, a garnish made of resin is attached to each of adjacent doors, and a screen is put on a garnish gap (i.e., a gap between the garnishes attached to the doors) so that door panels or body panels are invisible between the garnishes.
For example, Patent Document 1 discloses a door structure in which a flange part is formed at an end of one of the garnishes in a manner such that it extends toward the backside of the other garnish, so that ends of both garnishes overlap each other.    Patent Document 1: Japanese Unexamined Patent Application, First Publication No. H8-58383.
However, as a garnish made of resin has thermal expansion (or thermal extension), the size of the above flange part cannot be large in consideration of prevention of interference between the garnishes when the doors are closed. Therefore, a larger part is visible through the garnish gap, which degrades outward appearance. Additionally, as the interval between the closed doors should be large in consideration of prevention of interference, the appearance of a door gap line (i.e., a boundary line between the two doors) is inferior.